** Shares of mining company Perpetua Resources PPTA.O gain 4% to $13.73

** Company says it has submitted a formal application to the U.S. Export-Import (EXIM) Bank, seeking debt financing of up to $2 billion to construct its Idaho antimony and gold Stibnite project

** Application for $2 billion is higher than the up to $1.8 billion EXIM had offered in its letter of interest to PPTA last year

** PPTA says higher application amount reflects rise in estimated number of job-years and basic engineering work completed in Q1

** The U.S. Army Corps of Engineers on Monday gave the final federal permit for company's antimony and gold Stibnite project

** Including session's moves, PPTA shares up 28.6% YTD

(Reporting by Sumit Saha in Bengaluru)

((Sumit.Saha@thomsonreuters.com;))